E-mail this article

Sending your article

Your article has been sent.

There’s a funny quote in the press materials for Os Mutantes’ new album, “Haih or Amortecedor,’’ the Brazilian psychedelia band’s first studio recording in more than 30 years.

Guitarist Sérgio Dias, who’s now the group’s leader and only founding member, says the album is a “perfect vision of what Os Mutantes should sound like in the 21st century.’’

It’s funny - even to him, he admits - because no one expected Os Mutantes to survive the 1970s. And they didn’t. But the band - whose original lineup included Dias; his brother, Arnaldo Baptista on bass and keys; and magnetic lead singer Rita Lee - had a brilliant run in Brazil from 1966 until Dias finally snuffed it out in 1978, by which point Baptista and Lee had already left.

“I had no idea this would happen,’’ Dias says of the band’s surprising longevity. “We were just having fun and playing back then. We had no career idea or anything like that. We were just living.’’

Sensations in their homeland and largely unknown outside of it, Os Mutantes lived up to their name, which means “the Mutants.’’ Infusing their music with an absurdist sense of humor and a penchant for wild live shows, they embodied the late-’60s Tropicalia movement that nurtured other countercultural artists who would eventually become the Brazilian vanguard, including Caetano Veloso, Gilberto Gil, and Tom Zé.

Perhaps because Os Mutantes are so identified with that era, worldwide interest in the band three decades later is even sweeter to Dias. The original lineup hasn’t performed together since the ’70s, but Dias says Lee and Baptista have a standing invitation to rejoin the band: “Any one of the Mutantes are completely welcome at any time. Whenever they want, the door is open.’’

In the meantime, the band is now a seven-piece ensemble on the road for its first full US tour, which comes to Somerville Theatre Oct. 4, emboldened by a renewed appreciation for a group that once seemed destined for cult status.

But a funny thing happened to Os Mutantes on the way to obscurity. In the mid-2000s high-profile musicians - including Beck, David Byrne, Devendra Banhart, and the Flaming Lips - began talking about the band’s influence and the importance of its early records. There’s also the famous story of how Nirvana’s Kurt Cobain tried, unsuccessfully, to reunite the band in 1993 by writing a letter to Baptista.

Especially now, when musical fusion in the form of mash-ups, sampling, and cross-cultural pollination is more prevalent than ever, it’s easy to see what those artists admired about Os Mutantes’ music. Sounding in dire need of Ritalin, the group played fast and loose with rhythm and linear structures but always kept the music melodic and attuned to the Beatles’ classic songcraft.

The band, without Lee, reunited in 2006 for a show in London, but it wasn’t until it played the Pitchfork Music Festival a few months later that Dias got a broad sense of the full-blown interest in Os Mutantes, especially among younger generations.

“We saw 20,000 kids out there, and a bunch of them were trying to sing in Portuguese - like we used to do with the Beatles,’’ Dias says, laughing. “That was weird.’’

That momentum is likely to pick up with this past Tuesday’s release of “Haih or Amortecedor.’’ A brash blend of hard rock, electronica, and native Brazilian rhythms, the album retains much of Os Mutantes’ strident vision for controlled chaos.

Even the album’s title imparts a sense of heady experimentation. “Haih’’ is “raven’’ in the Shoshone language, a reference to Dias’s longtime fascination with crows and ravens and also the notion of magic and science fiction that’s always been associated with Os Mutantes. “Amortecedor’’ means “shock absorber’’ in Portuguese.

It would have been easy, and maybe even tempting, to record a classic Os Mutantes record that would have thrilled longtime and new admirers. But Dias held fast to a strict stipulation in the studio.

“We just didn’t look back,’’ Dias says. “We didn’t want to sound like anything we did before. That’s the only thing we were aware of - not to redo whatever we did.’’